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Message-ID: <1eca7836-2e90-0ed8-7556-fa6be057aad2@suse.cz>
Date:   Wed, 11 Jan 2023 15:05:27 +0100
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Subject: Re: [PATCH 5/7] mm/page_alloc.c: Allow __GFP_NOFAIL requests deeper
 access to reserves
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To:     Mel Gorman <mgorman@techsingularity.net>,
        Linux-MM <linux-mm@kvack.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@suse.com>, NeilBrown <neilb@suse.de>,
        Thierry Reding <thierry.reding@gmail.com>,
        Matthew Wilcox <willy@infradead.org>,
        LKML <linux-kernel@vger.kernel.org>
References: <20230109151631.24923-1-mgorman@techsingularity.net>
 <20230109151631.24923-6-mgorman@techsingularity.net>
From:   Vlastimil Babka <vbabka@suse.cz>
In-Reply-To: <20230109151631.24923-6-mgorman@techsingularity.net>
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On 1/9/23 16:16, Mel Gorman wrote:
> Currently __GFP_NOFAIL allocations without any other flags can access 25%
> of the reserves but these requests imply that the system cannot make forward
> progress until the allocation succeeds. Allow __GFP_NOFAIL access to 75%
> of the min reserve.
> 
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/page_alloc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 6f41b84a97ac..d2df78f5baa2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5308,7 +5308,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
>  		 * could deplete whole memory reserves which would just make
>  		 * the situation worse
>  		 */
> -		page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
> +		page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_MIN_RESERVE|ALLOC_HARDER, ac);
>  		if (page)
>  			goto got_pg;
>